A unique, patented door panel frame made of anodised aluminium with a thickness of 2 mm to 9 mm. This combination of metal helps to achieve strength for doors up to 3 meters high. Each corner is double reinforced with 2.5 mm plates. The geometry of the aluminium frame remains unchanged during the entire service life of the door.#nbsp; The hidden frame makes it possible for the door to be level with the wall.#nbsp;